Here in the western province of Alberta, energy companies are racing to tap the region’s vast deposits of oil sands. Canada is looking to double production by the end of the decade. To do so it will have to lure more workers — tens of thousands of them — to this cold and sparsely populated place. The weak U.S. recovery is giving them a big assist.

Canadian employers are swarming U.S. job fairs, advertising on radio and YouTube and using headhunters to lure out-of-work Americans north. California, with its 10.2% unemployment rate, has become a prime target. Canadian recruiters are headed to a job fair in the Coachella Valley next month to woo construction workers idled by…